AVEO and Astellas Announce Initiation of Patient Enrollment in Phase 2 Trial of Tivozanib in Combination with Paclitaxel in Patients with Advanced Triple Negative Breast Cancer

AVEO Oncology (NASDAQ: AVEO) and Astellas Pharma Inc. (TSE: 4503) today
announced the initiation of patient enrollment in a randomized,
double-blind, multicenter Phase 2 clinical trial, called BATON-BC,
evaluating the efficacy of tivozanib, an investigational drug, in
combination with paclitaxel compared to placebo in combination with
paclitaxel in patients with locally recurrent or metastatic triple
negative breast cancer who have received no prior systemic therapy for
advanced or metastatic breast cancer (mBC). Triple negative breast
cancer was selected for tivozanib clinical evaluation because of high
unmet need and insights gained from AVEO’s Human Response PlatformTM
indicating that these tumors are enriched for a signature of VEGF
pathway deregulation similar to that seen in renal cell carcinoma (RCC).
BATON-BC is the third trial to be initiated as part of the BATON (Biomarker
Assessment of Tivozanib
in ONcology) clinical development program,
which includes ongoing trials in advanced metastatic colorectal cancer
and advanced RCC.

“While currently available chemotherapy and hormonal therapies have
significantly enhanced the survival of women diagnosed with breast
cancer, there remains an unmet treatment need for those fighting
advanced triple negative breast cancer,” said Erica Mayer, M.D., M.P.H.,
director of Clinical Research, Dana-Farber/Brigham and Women’s Cancer
Center at Faulkner Hospital, assistant professor in medicine, Harvard
Medical School, and BATON-BC primary investigator. “The BATON-BC trial
is designed to evaluate progression-free survival as well as improve our
understanding of triple negative breast cancer by providing us with the
opportunity to identify the patients who are most likely to be
responsive or resistant to tivozanib therapy.”

BATON-BC, which is being led by AVEO, is a double-blind,
placebo-controlled, randomized (2:1 tivozanib/placebo), multicenter
study that will enroll approximately 147 patients at 50 sites worldwide.
The primary endpoint of BATON-BC is progression-free survival (PFS).
Secondary objectives include evaluation of objective response rate,
overall survival and safety. An additional component of BATON-BC is the
evaluation of biomarker relationships that may be predictive of clinical
response to tivozanib in patients with triple negative breast cancer.

“While tivozanib is currently under review with the FDA for advanced
RCC, we’re committed to investigating the development of tivozanib
beyond advanced RCC,” said Stephen Eck, M.D., Ph.D., Vice President of
Medical Oncology, Astellas Pharma Global Development. “At Astellas, we
are committed to discover and develop molecularly targeted therapies and
precision medicines that have the potential to revolutionize the methods
used to treat cancer patients.”

Data from a Phase 1b clinical trial of tivozanib (0.5 mg - 1.5 mg per
day for three weeks, followed by one week off, repeating at a cycle of
28 days) in combination with weekly paclitaxel (three weeks on, followed
by one week off) in patients with metastatic breast cancer demonstrated
that the combination was considered tolerable at the full dose and
schedule of both agents (tivozanib 1.5 mg and paclitaxel 90 mg/m2),
and resulted in an objective response rate of 38% (5/13 patients). In
the study, 54% (7/13) of patients had stable disease (SD), with a median
duration of SD of 8.5 months (range: 4.2–10.7).1

“Currently there are no approved targeted therapies for the treatment of
triple negative breast cancer. Biomarkers derived from AVEO’s Human
Response Platform will be evaluated for potential use in identifying
breast cancer patients who will be most likely to benefit from treatment
with tivozanib,” said William Slichenmyer, M.D., Sc.M., chief medical
officer at AVEO. “Following the FDA’s recent acceptance of a New Drug
Application seeking approval for tivozanib in advanced RCC, we remain
committed to expanding the development of tivozanib in additional solid
tumor types, and look forward to further evaluating tivozanib as a
potential new treatment option for patients living with triple negative
breast cancer.”

About Triple Negative Breast Cancer

Globally, breast cancer is diagnosed in about 1.4 million women annually
and about 230,000 women annually in the United States.2About
1 in 8 women will develop invasive breast cancer during their lifetime.3

Triple negative breast cancer is comprised of tumors that do not express
the estrogen receptor, progesterone receptor or the human epidermal
growth factor receptor-2 and accounts for approximately 12-20% of breast
cancers.2,3 Receptor expression is typically confirmed at the
time of a breast cancer diagnosis. There are currently no approved
targeted therapies for triple negative breast cancer.

About Tivozanib

Tivozanib is a potent, selective and long half-life inhibitor of all
three vascular endothelial growth factor (VEGF) receptors that is
designed to optimize VEGF blockade while minimizing off-target
toxicities. Tivozanib is an oral, once-daily, investigational tyrosine
kinase inhibitor for which positive results from a Phase 3 clinical
study in advanced RCC have been reported, and is being evaluated in
other tumors.

About BATON-BC

BATON-BC is a double-blind, placebo-controlled, randomized (2:1
tivozanib/placebo), multicenter study that will enroll approximately 147
patients at 50 sites worldwide. The trial compares PFS of triple
negative breast cancer patients treated with tivozanib in combination
with paclitaxel versus placebo in combination with paclitaxel. Secondary
objectives include evaluation of objective response rate, overall
survival and safety. Additional exploratory objectives include the
evaluation of potential tumor biomarkers predictive of tumor sensitivity
and/or resistance to tivozanib in combination with paclitaxel and
effectiveness of tivozanib in combination with paclitaxel in defined
intrinsic molecular breast cancer subtypes.

About the AVEO/Astellas Collaboration

In February 2011, AVEO and Astellas entered into a worldwide agreement
to develop and commercialize tivozanib outside of Asia for the treatment
of a broad range of cancers. Tivozanib, AVEO's lead investigational
drug, is a potent, selective, long half-life inhibitor of all three VEGF
receptors that is designed to optimize VEGF blockade while minimizing
off-target toxicities. Subject to regulatory approval, AVEO will lead
commercialization of tivozanib in North America and Astellas will lead
commercialization of tivozanib in the European Union (EU).

About Astellas

Astellas Pharma Inc., located in Tokyo, Japan, is a pharmaceutical
company dedicated to improving the health of people around the world
through the provision of innovative and reliable pharmaceuticals.
Astellas has approximately 17,000 employees worldwide. The organization
is committed to becoming a global category leader in Urology, Immunology
(including Transplantation) and Infectious Diseases, Oncology,
Neuroscience and DM Complications and Kidney Diseases. For more
information on Astellas Pharma Inc., please visit the company website at www.astellas.com/en.

About AVEO

AVEO Oncology (NASDAQ: AVEO) is a cancer therapeutics company committed
to discovering, developing and commercializing targeted therapies to
impact patients' lives. AVEO's proprietary Human Response PlatformTM
provides the company unique insights into cancer biology and is being
leveraged in the discovery and clinical development of its cancer
therapeutics. For more information, please visit the company's website
at www.aveooncology.com.

Cautionary Note Regarding Forward-Looking Statements

This press release contains forward-looking statements within the
meaning of The Private Securities Litigation Reform Act of 1995 that
involve substantial risks and uncertainties. All statements, other than
statements of historical facts, contained in this press release are
forward-looking statements. The words “anticipate,” “believe,”
“estimate,” “expect,” “intend,” “may,” “plan,” “target,” “potential,”
“could,” “should,” “seek,” or the negative of these terms or other
similar expressions, are intended to identify forward-looking
statements, although not all forward-looking statements contain these
identifying words. These forward-looking statements include, among
others, statements about: tivozanib’s potential role in treating
patients with triple negative breast cancer; the BATON-BC trial
improving AVEO’s understanding of triple negative breast cancer; the
estimated enrollment of BATON-BC; assessing biomarkers to predict
clinical response to tivozanib in patients with triple negative breast
cancer; developing medicines that revolutionize the methods used to
treat cancer patients; plans by AVEO and Astellas to commercialize
tivozanib in North America and the EU, respectively; expanding the
development of tivozanib in additional solid tumor types; and AVEO’s
plans to leverage its Human Response Platform. Actual results or events
could differ materially from the plans, intentions and expectations
disclosed in the forward-looking statements that AVEO makes due to a
number of important factors, including risks relating to: whether the
results of AVEO’s Phase 3 TIVO-1 trial (TIvozanib
Versus sOrafenib
in 1st line
advanced RCC) are sufficient to obtain marketing approval for tivozanib,
which turns on the ability of AVEO to demonstrate to the satisfaction of
the FDA or comparable foreign regulatory authorities the safety and
efficacy of tivozanib based upon the findings of TIVO-1, including its
data with respect to PFS, the rate of adverse events, overall survival
and other information that the FDA may determine to be relevant to
approvability; AVEO’s ability to demonstrate in subsequent trials any
safety and efficacy it demonstrated in earlier trials of tivozanib;
ongoing regulatory requirements with respect to the approval of
tivozanib, including the risk that the FDA or any comparable foreign
regulatory agency could require additional positive clinical trials as
the basis for product approval; AVEO’s ability to obtain and maintain
adequate protection for intellectual property rights relating to its
product candidates and technologies; unplanned operating expenses;
AVEO’s ability to raise the substantial additional funds required to
achieve its goals; adverse general economic and industry conditions;
competitive factors; AVEO’s ability to maintain its collaboration with
Astellas; AVEO’s and Astellas’ ability to successfully launch and
commercialize tivozanib if and when it may be approved for
commercialization; and those risks discussed in the section titled “Risk
Factors” and elsewhere in AVEO’s most recent Quarterly Report on Form
10-Q and in its other filings with the Securities and Exchange
Commission. The forward-looking statements in this press release
represent AVEO’s views as of the date of this press release. AVEO
anticipates that subsequent events and developments will cause its views
to change. However, while AVEO may elect to update these forward-looking
statements at some point in the future, it specifically disclaims any
obligation to do so. You should, therefore, not rely on these
forward-looking statements as representing AVEO’s views as of any date
subsequent to the date of this press release.